This document provides an overview of dengue fever, including: 1. It describes the dengue virus, its vector Aedes aegypti mosquito, and the disease's pathogenesis and clinical presentations ranging from mild dengue fever to severe dengue hemorrhagic fever and dengue shock syndrome. 2. It outlines the laboratory diagnosis and management approach divided into three groups - outpatient, inpatient, and emergency treatment groups. 3. It discusses treatment approaches for different clinical stages of the disease as well as vector control methods and the status of vaccine development.

1. A comprehensive presentation
by
DR MANDAR HAVAL
DR SANDIP KADE

2. Alternative Names
• Onyong- Nyang Fever
• West Nile Fever
• Break Bone Fever
• Dengue like Disease

3. Dengue fever
• Etiology
• Epidemiology
• Pathogenesis
• Clinical presentation
• Classification of disease spectrum
• Diagnosis
• Management

4. The Dengue Virus
• Flavivirus
• Positive sense
• Single stranded RNA virus
• 40 to 50 nanometers
• Four sero-sub types
• Type 1 to 4
• Arthropod borne

5. Dengue Virus
Electron Micrograms

6. Dengue Virus
Cell Culture
Of Dengue
Virus

7. The Vector
Aedes aegypti
(Infected Female Mosquito)
(rarely Aedes albapticus)

8. Aedes aegypti
Dengue, YF,
CGF

9. Peculiarities of A.aegypti
• It is a day biting mosquito when normally
coils, repellents, nets etc are not used
• It breads in fresh water around homes
• Lays eggs preferentially in water jars, discar-
ded containers, coconut shells, old tires etc.
• Can transmit trans-ovarially the infection
• Year round breeding 250 N to 250 S
• Tropics and sub-tropics are its favorite zones.
It is an urban vector

10. Pathogenesis
Increased vascular permeability
Bone marrow suppression
Decreased levels of anticoagulants

11. Pathogenesis
Dengue Infection
Infected monocytes
Vasoactive mediators
Increased vascular permeability
Plasma leaking & hemoconcentration

12. Pathogenesis
Bone marrow supression
Leucopenia
Thrombocytopenia
Neutropenia

13. Pathogenesis
• Decreased levels of fibrinogen , prothrombin
factor II , VII ,IX, X ,XII, Antithrombin III
• Disseminated intravascular coagulation
• PT ,PTTK,TT may be normal or increased .
• C3 & C5 levels decreased and C3a & C5a elevated

14. Causes of THROMBOCYTOPENIA
• Depression of bone marrow leading to impaired production
of megakaryocyres
• Increased platelet destrucion :
virus itself
circulating immune complexes
and antiplatelet antibodies
• Periferal sequesrtation and consumption :
as in DIC

15. Causes of hemorrhagic
manifestation
• Vascular instability
• Decreased vascular integrity
• Assault on macro vasculature
• Decreased platelet function
• Increased vascular permeability
• Vascular disruption and local bleeds

16. Spectrum of clinical Presentations
• Undifferentiated fever
• Dengue Fever (DF) with the Fever- Myalgia
(FM) presentation (classical)
• Dengue Hemorrhagic Fever (DHF)
• Dengue Shock Syndrome (DSS)

17. Undifferentiated fever
• First infection with dengue virus presents with
undifferentiated viral illness.
• Maculopapular rash during the fever or during
defervescence
• Nausea vomiting and myalgia

18. Dengue fever
• IP of 2 – 7 days
• Sudden onset of fever, chills, headache
• Anorexia. Nausea, vomiting
• Back pain with severe myalgia, arthralgia
• Retro-orbital pain – break bone fever
• Macular rash – in axillary area
• Maculo - papular rash on trunk – extremities
• Leucopenia

19. Dengue Hemorrhagic fever
1. Fever or history of acute fever lasting 2-7 day
occasionally biphasic
2. Hemorrhagic tendencies evidenced by at least
one of the following :
~Positive torniquet test
~Petichiae ,ecchymosis, purpura
~Bleeding from mucosa and GIT
~Hematemesis maleana
~Thrombocytopenia

20. Dengue Hemorrhagic fever
3 . Thrombocytopenia < 100000/mm3
4 . Plasma leakage evidenced by atleast one
~Rise in hematocrit > 20 %
~ Fall in hematocrit > 20% after IV fluids
~Plural effusion,acites,hypoalbunemia

21. Dengue shock syndrome
• All four DHF Criteria plus
• Signs of circulatory failure as:
> Rapid and weak pulse
> Narrow pulse pressure { < 20 mmHg }
> Hypotension
> Cold clammy skin , restlessness

22. Earlier WHO classification

24. Four Grades of DHF/DSS
• Grade 1
Fever, Const. Symptoms, +ve tourniquet test
• Grade 2
Grade 1 + Spontaneous bleeding
• Grade 3
Signs of circulatory failure
• Grade 4
Profound shock - B.P. Pulse not recordable

25. Petechiae

26. Ecchymosis – Periorbital Edema

27. Large Subcutaneous Bleed

28. Capillary Damage

29. Unusual Presentations of Dengue
• Encephalopathy
• Hepatic damage
• Cardiomyopathy
• Severe GI bleeding

30. DHF- Poor Prognostic Signs
• Girl children under 12 with DHF/DSS
• Severe hypotension and shock
• Multifocal bleeding – abdominal pain
• CNS encephalopathy ,fits ,coma
• Watch for preorbital edema, proteinuria
postural or otherwise hypotension
• Serotype 2 infection after type 4
• Malnutrition is PROTECTIVE

31. Laboratory Diagnosis
• Complete Blood Counts
• Hematocrit
• Platelet Count
• SGOT, SGPT
• Serum Albumin
• Urine for Protein , hematuria
• Immunological Tests
• Chest X ray

32. Laboratory Diagnosis
• Leucopenia. Thrombocytopenia
• Increased SGOT, SGPT
• Rising Ab titre in paired sera
• NS1 detection ELISA(<3days)
• IgM -capture ELISA within(3-5 days)
• IgG ELISA significant of past infection
• Reverse transcription PCR confirmatory

33. Management
• Group A – patient who may be sent home.
• Group B – patient who needs in hospital
management.
• Group C – Patients who need emergency
treatment and Intensive care.

34. Group A
• Ambulatory patients - Able to tolerate fluids
• Adequate urine output
• No warning signs
• Rx
• Reviewed daily for disease progression { warning signs
hct and leucopenia }
• Plenty of oral fluids
• Antipyretics {aspirin, ibuprofen NSAIDS should be
avoided – gastritis and bleeding}
• Immediate consultation for severe abdominal pain
vomitings cold clamy limbs black stools and oligourea

35. Group B
• Patients with warning signs or those
with co-existing that may make
dengue or its management more
complicated (infancy, dual infection,
or congenital anomalies)

36. Group B
• Rx
• Obtain baseline hematocrit before IV fluids
• Start with 5-7 ml/kg for 1-2 hours
• Reduce to 3-5 ml/kg for 2-4 hours
• Reduce to 2-3 ml/kg/hr as per clinical
response and urine output .
• Isotonic solutions should be preferred.

37. Group C
• Pt who require emergency treatment and
urgent referral
• Severe Plasma leakage, severe
HEMORRHAGES, severe organ impairment.

38. Treatment Of Compensated Shock

40. Treatment of hypotensive shock

42. Monitoring during T/t of shock
• Vitals { pulse oxymetry }
• ECG
• Arterial blood gas
• Sr. lactate
• Blood glucose level
• LFTs and KFT
• Coagulation profile

43. Risk of bleeding
• Patient at risk of major bleeding
• Renal & Hepatic failure & persistent metabolic
acidosis
• NSAID Therapy
• Pre existing peptic disease
• On anticoagulant therapy
• Any trauma including IM Injection

44. Treatment of hemorrhagic
complication
• No IM injections
• Strict bed rest
• Blood transfusion is life saving but should be
used cautiously
• Platelet in case of profound thrombocytopenia
and active bleeding
• Maintainace of perfusion of vital organs with
judicious use of crystalloid and colloids

45. Management of fluid overload
• Causes :
• Excessive and too rapid IV fluids
• Incorrect use of hypotonic fluids rather than
isotonic crystalloids
• Inappropriate use of FFP & platelet conc. And
cryoprecipitate
• Continued IV fluids after plasma leakage has
restored
• Co morbidities{CHD chronic lung or renal disease}

46. How to deal
• Depends on phase of disease and according to
hemodynamic status of patient
• HD stable and out of critical phase > STOP IV
fluids instantly and continue close monitoring.
• If necessary IV or ORAL furoseamide along
with monitoring of eletrolytes
• Fresh Blood Transfusion advise in low or
normal Hct. But shows s/o volume overload

47. Cont….
• Small boluses of collides are preffered in pt
with shock with elevated Hct.

48. Adjuvant Therapy
• Vasopressor and inotrops ( fluid refrac..)
• Renal replacement therapy in ARF
• Treatment of complication like LIVER FAILURE
and ENCEPHALOPATHY

49. Is there any role of Platelets ????
• NO….
• Indicated only in Pt with active BLEED or
PROFOUND THROMBOCYTOPENIA (<10,000)

50. Is there role of STEROID??????
• NO….

51. Choice Of Iv Fluids
• Crystalloids – NORMAL SALINE(300), RINGER
LACTATE(273)
• NS – is ideal for initial ressucitation but if
continued there is a risk of hyperchloremic
acidosis
• RL – its may be not sutaible for initial ressuci..
But is continued as a maintainance fluid.
Contraindicated in liver failure..

52. Colloids
• Indicated in Narrow pulse pressure shock, if
Blood pressure has to be restore urgently.
• It improves cardiac index and Hct in
intractable shock

53. RCT on CRYSTALOID V/S COLLOIDS
• No CLEAR ADVANTAGE of
colloids over crystalloid

54. Vector Control of Dengue
• Mosquito control is expensive –impossible
• Destruction of breeding sites – viable
• Individual measures to avoid vector contact
1. Mosquito screens, repellents (DEET)
2. Permithrin impregnated clothing
• Non degradable tires, long life plastics-avoid

55. Immunization
• Each serotype produces life
long immunity
• Vaccine needs to be tetravalent
• A live-attenuated tetravalent vaccine based on
chimeric yellow fever-dengue virus (CYD-TDV),
has progressed to phase III efficacy studies.
• It may be harmful to vaccinate in view
of the pathogenesis of DHF/DSS
(Sanofi Pasteur)

56. • Each Patient is a Book
• Each Day is a Learning Opportunity
• CME has More Relevance
Now Than Ever
Together We Learn Better